The Biostatistics and Database Management Core, under the direction of Dr. Helena Chmura Kraeumer, provides biostatistical, epidemiological, and methodological consulting services and support, and central database management for the Center. The data collected in each Core are stored in a single database. Collaborating Cores can access data and obtain analytic support via the Biostatistics and Database Management Core. The staff of the Biostatistics and Database Management Core perform data management tasks (such as data entry, and correction), archive datasets, and help carry out statistical analyses. The latter function is especially important when analyses are complex and when data core from several investigators. The design, development, and maintenance of the Center data hardware and software systems are the responsibility of the Biostatistics and Database Management Core. This Core also assures quality control, confidentiality, and physical security of all Center datasets. This Core also provides consultation on research design, measurement, and analysis. It identifies methodological problems relevant to ongoing research efforts of both Core and Associate Investigators and develops or recommends methodology specific to the types of research projects supported by the Center.